What is mesh? What is mesh? Any of the open spaces in a net or network; an interstice.The cords, threads, or wires surrounding these spaces. Often used in the plural.An openwork fabric or structure; a net or network: a screen made of wire mesh. Something that snares or entraps. Often used in the plural: "Arabia had become entangled in the meshes of . . . politics” ( W. Montgomery Watt). The engagement of gear teeth.The state of being so engaged: gear teeth in mesh. To catch in or as if in a net; ensnare.To cause (gear teeth) to become engaged.To cause to work closely together; coordinate.To become entangled.To become engaged or interlocked: gears that are not meshing properly. To fit together effectively; be coordinated.To accord with another or each other; harmonize.